A filter medium is provided. According to one embodiment of the present invention, the filter medium is implemented by including: a porous second support and a nanofiber web which are sequentially stacked on each of an upper portion and a lower portion of a first support; and a channel through which a filtrate filtered in the nanofiber web flows in a direction of the first support, wherein the first support, the second support, and the nanofiber web satisfy predetermined conditions on a basis weight and a thickness of each layer. In a water treatment operation of the filter medium, the shape, structural deformation, and damage of the filter medium can be minimized, excellent filtration efficiency can be implemented, and a channel can be smoothly secured, thereby securing high flux. In addition, even at high pressure applied during backwashing, the filter medium has an extended use period due to excellent durability of the filter medium. Accordingly, the filter medium can be variously applied in various water treatment fields.

A dual-layer membrane and a method for preparing thereof. By adding a modifying monomer containing an active group and a characteristic group to a dope solution or spinning solution during the preparation of the dual-layer membrane, the grafting reaction occurs between the active group of the monomer and the polymer in the dope solution or spinning solution, and the intermolecular interaction with other polymers is enhanced by the characteristic group of the monomer, to improve the miscibility between the polymers. The method is suitable for preparing both a dual-layer flat sheet membrane and a dual-layer hollow fiber membrane, and can realize the preparation of a dual-layer membrane with an interpenetrated structure at the interface under mild preparation conditions.

A manufacturing method for an acidic gas separation membrane sheet includes: a step of preparing a hydrophilic resin composition liquid for forming a hydrophilic resin composition layer; a step of removing bubbles contained in the hydrophilic resin composition liquid; a step of applying the hydrophilic resin composition liquid onto a first porous layer to form an applied layer on the first porous layer; and a step of laminating a second porous layer on the applied layer to form a laminated body. The step of removing bubbles includes: a step of applying a shear to the hydrophilic resin composition liquid; and a step of leaving the hydrophilic resin composition liquid.

A filter medium is provided. A filter medium according to an embodiment of the present invention comprises: a fiber web layer of a three-dimensional network structure including nanofiber; and a hydrophilic coating layer which covers at least a part of the outer surface of the nanofiber. According to this, a flow rate can be remarkably increased due to the improved hydrophilicity of the filter medium. Also, as the improved hydrophilicity is maintained for a long period of time, the lifespan can be remarkably prolonged. Furthermore, since the modification of a porous structure of the filter medium is minimized during the process of hydrophilization so that the initially designed physical properties of the filter medium can be exhibited in its entirety, the filter medium having chemical resistance, excellent water permeability and durability can be variously applied in the water treatment field.

Disclosed is a semipermeable membrane and its preparation method. The semipermeable membrane obtained has a Turing structure. The Turing structure is an ordered pattern composed of microstructures. The existence of the structure enables the semipermeable membrane of this invention to have both high water permeation flux and excellent salt retention performance, which breaks the flux limit value of the semipermeable membrane while ensuring high selective permeability of the membrane. It also has good anti-pollution properties. The preparation method of the invention can be easily integrated into the existing semipermeable membrane production line without further cost input which has far-reaching practical significance and commercial value.

An industrial wastewater filtration membrane and method for manufacture is disclosed herein. The membrane has three layers: a support layer of nonwoven fabric such as PET, a polysulfone nanofiber filtering membrane layer, and a nanoporous polyamide active separating layer. The polysulfone layer is electrospun onto the support layer. The polyamide layer is electrosprayed onto the polysulfone layer. The resulting membrane has a pure water flux rate of at 0.48 MPa that is between 40-200 liters per square meter per hour, a rejection rate of sodium chloride of 10-85% with inlet sodium chloride concentration of 2000 ppm, and a rejection rate of magnesium sulphate of 80-97% with inlet magnesium sulphate concentration of 2000 ppm.

The invention relates to a self-supporting highly moisture-permeable heat-insulating aerogel film and a preparation method thereof. The aerogel film is a self-supporting single-layer film with a SiO.sub.2 porous skeleton structure, having a thickness of 150 m to 300 m, which increases an exchange rate of vapor by 50% to 200%, and reduces a heat conductivity coefficient by 50% to 90%. The preparation method includes the following steps: (1) preparation of a template; (2) hydrolysis of nano-cellulose; (3) preparation of an aerogel film; and (4) post-treatment of the aerogel film.

A process for manufacturing a porous body, includes preparing a dispersion liquid having a dispersion medium with cellulose-based nanofibers that have an average fiber diameter from 1 to 100 nm and dispersed therein, attaching the dispersion liquid to a porous support having a plurality of pores that connect with one another, removing the dispersion liquid attached to a surface of the porous support excluding an inside of pores of the porous support, and subsequently drying the porous support including the dispersion liquid in the pores of the porous support to remove the dispersion medium.

Provided is a method for preparing a gas separation membrane, the method including forming a porous layer by coating a hydrophilic polymer solution on a porous substrate; and forming an active layer by coating a composition for forming an active layer including a polymer of Chemical Formula 1 on the porous layer,

##STR00001## wherein in Chemical Formula 1, n is the number of a repeating unit, and is an integer of 500 to 3,000, and R1 to R5 are the same as or different from each other, and each independently is hydrogen, an alkyl group, or (CO)R6, and R6 is an alkyl group, wherein the polymer of Chemical Formula 1 is included in an amount from 1% by weight to 5% by weight based on the composition for forming an active layer, and a gas separation membrane prepared using the same.

Disclosed herein are composite membranes comprising an omniphobic substrate having a reentrant structure. The omniphobic substrate comprises a plurality of pores, the plurality of pores forming the reentrant structure. The omniphobic substrate further comprises a surface, the surface being coated with a dual functional layer that is hydrophilic in air and oleophobic under water, such that the composite membrane has a top portion and a bottom portion, the top portion comprising the coated surface of the omniphobic substrate, such that the top portion of the composite membrane is hydrophilic in air and oleophobic under water and the bottom portion of the composite membrane is omniphobic. The composite membrane can be antiwetting and/or antifouling in the presence of a hydrophobic contaminant, an amphiphilic contaminant, or a combination thereof. The composite membranes can be used for membrane distillation of a contaminated brine solution.